A skin neoplasm is an unusual growth on your skin. The word neoplasm is sometimes used interchangeably with cancer, but neoplasms can also be noncancerous. You might also hear neoplasms referred to as tumors.

The cells in your skin grow and divide as needed. When you don’t need them anymore, they die. However, sometimes cells continue to grow when they shouldn’t. This causes neoplasms.

There are many ways to categorize neoplasms. One of the main distinctions is whether a neoplasm is benign or malignant.

Benign neoplasms

A benign neoplasm grows where it started and doesn’t spread to nearby tissues or other parts of your body. However, it can still damage the organs and tissues around it. Benign neoplasms are noncancerous.

It’s important to note that some benign neoplasms can turn into cancer. Even if you’ve been diagnosed with a benign neoplasm, it’s best to keep an eye on it and report any changes about its appearance to your doctor right away.

Types of benign skin neoplasms include:

Malignant neoplasms

A malignant neoplasm is cancerous. Unlike benign neoplasms, malignant neoplasms grow uncontrollably and can invade other organs. They can also travel through your body and produce new tumors.

Types of malignant skin neoplasms include:

Some neoplasms are considered precancerous. While some doctors use the term in slightly different ways, it generally means that a neoplasm may turn into cancer if left untreated. In some cases, these growths go away on their own, but sometimes they may gradually turn into cancer.

For example, actinic keratosis (AK), also called solar keratosis, involves rough, scaly growths that form on skin that’s been exposed to ultraviolet light. AKs can sometimes resemble warts. They may be pink or flesh-colored. If left untreated, they can turn into a type of squamous cell skin cancer.

Another common precancerous growth is squamous cell carcinoma in situ, sometimes called Bowen's disease. Latin for “in its original place,” in situ means that the unusual cells are only in the upper layer of skin called the epidermis. Squamous cell carcinoma in situ often forms as red, scaly patches that can itch. When left untreated, it can turn into squamous cell carcinoma.

In addition to being labelled as malignant or benign, some neoplasms are categorized as having uncertain behavior. This means your doctor needs more information to determine whether your neoplasm is malignant or benign. In other words, they don’t know whether it has the potential to spread.

If your doctor finds a neoplasm of uncertain behavior, they’ll likely perform a biopsy. This involves taking a small tissue sample from the affected area and testing it for cancer.

Whether or not you have a skin neoplasm, it’s important to regularly check your skin for any new growths. Once a month, stand in front of a mirror and examine your entire body, including hard-to-see areas, such as the back of your neck and the bottoms of your feet.

The American Academy of Dermatology has a downloadable body map and chart you can use to keep track of any growths you find. Taking regular notes will also help you stay on top of any changes.

You can guide your self-exam by following the ABCDE method for detecting melanoma, the deadliest type of skin cancer. Each letter corresponds to a trait you should look for:

  • Asymmetry. The mole is shaped differently on one side than the other.
  • Borders. The edges of the mole are uneven.
  • Color. The mole contains different colors or different shades of the same color.
  • Diameter. The mole measures more than ¼ inch (about the size of a pencil eraser).
  • Evolving. The mole has changed size, shape, or color since you last looked at it.

Additional signs to watch for include:

  • a change in the spot’s texture
  • a spot that itches, crusts over, scabs, or bleeds
  • an open sore that doesn’t heal within three weeks

If you find any of these traits anywhere on your body, contact your doctor as soon as possible. While these signs don’t necessarily mean you have skin cancer, it’s best to get it checked out immediately. The earlier skin cancer is diagnosed, the easier it can be to treat. Learn more about screening yourself for skin cancer.

If you notice any sort of new growth on your skin, it’s best to make an appointment with a dermatologist. You can ask your doctor to refer you to one.

During your appointment, your dermatologist will likely ask questions about your medical history and lifestyle. Make sure to tell them about anything that might increase your risk of skin cancer, such as having:

  • a fairer skin color
  • a family history of skin cancer
  • a history of using tanning beds
  • a large number of moles
  • skin that easily burns or develops freckles
  • a history of sunburns, especially as a young child

Next, they’ll take a look at the spot in question. Depending on what they see, they may do a biopsy to determine whether it’s benign or malignant.

There are three main types of skin biopsy:

  • Shave biopsy. This method uses a small blade to shave off the top layers of your skin.
  • Punch biopsy. Your doctor uses a circular tool to remove a small, circular piece of both the top and deeper layers of your skin.
  • Excisional biopsy. This method uses a small knife to remove both the growth and a small amount of your skin around it.

Your dermatologist will send your skin sample to a laboratory where it’ll be tested for cancer. Once they have the results, they’ll go over them with you and help you determine a treatment plan if needed. Learn more about what to expect during a biopsy for skin cancer.

A skin neoplasm is an unusual growth on your skin. They’re often categorized as benign, malignant, or precancerous. You might also hear your doctor refer to uncertain behavior if they’re not completely sure about whether a neoplasm is cancerous or not.

Regardless of whether you have an existing skin neoplasm, it’s good to get in the habit of doing regular skin self-exams to check for any new growths or changes to old ones.